Which error of meter bridge is removed when the known and unknown resistances are interchanged?

Options

A. End error
B. Measurement error
C. Percentage error
D. Parallax error

Explanation

To solve the question, we need to analyze the types of errors that can occur in a meter bridge experiment and understand how interchanging the known and unknown resistances affects these errors.

### Step-by-Step Solution:

1. **Understanding the Meter Bridge**: A meter bridge is a device used to measure unknown resistances by balancing them against known resistances. It operates on the principle of Wheatstone bridge.

2. **Types of Errors in Meter Bridge**:
- **AND Error**: This error arises due to the non-ideal behavior of the bridge, particularly when the resistances are not perfectly balanced.
- **Measurement Error**: This refers to inaccuracies in reading the values from the bridge.
- **Percentage Error**: This is a way to express the error as a percentage of the measured value.
- **Parallax Error**: This occurs when the measurement is read from an angle rather than directly in line with the scale.

3. **Interchanging Known and Unknown Resistances**: When we interchange the known and unknown resistances, we essentially change the positions of the resistances in the circuit. This can affect how the bridge is balanced.

4. **Effect on AND Error**: The AND error is specifically related to the balance condition of the meter bridge. When the resistances are interchanged, the balance point shifts, and any systematic error associated with the measurement of one resistance is effectively canceled out. This means that the AND error is eliminated when the resistances are swapped.

5. **Conclusion**: Therefore, the error that is removed when the known and unknown resistances are interchanged in a meter bridge is the **AND Error**.

### Final Answer:
The error that is removed when the known and unknown resistances are interchanged in a meter bridge is the **AND Error**.

---